[STRIKE]For part b, I'm getting that Z = 0 simply by substituting in [itex]\omega[/itex].
Is this correct? [/STRIKE]

This gives an impedance of [itex]\infty[/itex]

I feel more confident is this answer. I'm guessing that the current in the capacitor and inductor are out of phase by [itex]\pi[/itex] causing what appears to be an infinite impedance. I'm still curious as to the exact reason though, if anyone could lend help. Thanks!